34 OP THE ROOT. 



Of the Hoot. 



The root (radix) is that part of the vegetable which enters the 

 earth, and extends in a direction contrary to the growth of the stem ; 

 it supports the plant in an upriglit position, and at the same time 

 gives nourishment to every part of it. There are exceptions to the 

 general fact, of a root being fixed in the ground ; some plants, as 

 the pond-Uly, grow in water, and are called aquatic, (from aqua, wa- 

 ter,) some, like the mistletoe, have no root, but fix themselves upon 

 other plants, and derive sustenance from them ; such are called par- 

 asites* 



The Root consists of two parts, the Caridex, or main body of the 

 Root, and the Radicle, or fibres j these are capillary tubes, which ab- 

 sorb the nourishment that is conveyed to other parts of the plant. 

 This nourishment ascending through the stem, experiences in the 

 leaves and green parts of the plant, an important change, effected, in 

 part, through the agency of air and light; and a portion of it, 

 through a different set of vessels, flows back, in what is called the 

 returning sap, or cambium. 



Between the Caudex and stem is a point, called the neck, or root 

 stock; any injury to this part is fpUowed by the death of the plant. 



Duration of Roots. 



Roots, with respect to duration, are annual, biennial, or peremiiaL 



Annual Roots — are such as live but one j/ear. They come from 

 the seed in the spring, and die in autumn, including such as are 

 raised from the seed every year ; as peas, beans, cucumbers, &,c. 



Biennial Roots — are such as live two years. They do not produce 

 any flowers the first season, the next summer they blossom, the seeds 

 mature, and the roots die. The roots of cabbages are often, after 

 the first season, preserved in cellars during the winter. In the spring 

 they are set out in gardens, and produce flowers ; the petals of 

 which, in time, fall off, and the germ grows into a pod which con- 

 tains the seed. The root having performed this office, then dies, 

 and no process can restore it to life ; the flowering is thought to ex- 

 haust the vital energy or living principle. The onion, beet, and 

 carrot, are biennial plants. 



Perennial Roots — are those whose existence is prolonged a num- 

 ber of years to an indefinite period; as the asparagus, geranium, 

 and rose ; also trees and shrubs. Chmate and cultivation affeci ^he 

 duration of the roots of vegetables. Many perennial plants become 

 annual by transplanting them into cold climates : the garden nastur- 

 tion, originally a perennial shrub in South America, has become 

 in our latitude an annual plant. 



Forms of Roots. 



There are many varieties in the forms of roots ; the most impor- 

 tant are the branching, Jibrous, spindle, creeping, gramdated, tuber- 

 ous, and bulbous. 



1st. Branching root, (Fig. 12.) This is the inost common kind; it 

 consists of numerous ramifications, resembling in appearance the 



* The word parasite, from the Greek para, with, and sites, corn, was first applied 

 to those who had the care of the corn used in religious ceremonies, and were allowed 

 a share of the sacrifice ; afterward it was applied to those who depended on the 

 great, and earned their welcome by flattery ; by analogy, the term is now applied to 

 plants which live upon others. 



Definition of the root— Aquatic roots— Parasites— Division of the root— Annual roots 

 —Biennial— Perennial roots— Classification of roots as founded upon their forms-' 

 Branching root. 



